My guess is that we need to be able to push certain things from inner queries to outer ones.  So, within SQL we have sort, dir, limit, offset. found_by is likely the most common source of this kind of weirdness, but we probably want a solution that does this regardless.

My guess is that the best idea is to use the outermost version of each of these that we have.

Outside of SQL we have append and view.  Separate issues, I suppose.